Extant species of amphibians not only survived the Pleistocene, but ancestral species withstood environmental changes that occurred in the Pliocene, Miocene, Oligocene, Eocene, Paleocene, Cretaceous, Jurrassic, and Triassic. They may be physiologically primitive, but they’re adaptable. Part of their ability to endure gross environmental change may be their habit of becoming dormant during unfavorable conditions such as drought or cold weather. Amphibians can burrow into mud or forest litter, under rocks, or at the bottom of a pond and are thus protected, even if the atmosphere cooks following an extraterrestrial impact.
Amphibian fossils of extant species occur in some Georgia fossil sites. Cavers and scientists found and identified 17 species of amphibians in Kingston Saltpeter Cave, Bartow County. Amphiuma fossil bones associated with mammoth and bison fossils were among the treasures of the Clark Quarry fossil site near Brunswick. Numerous fossil localities in South Carolina’s coastal plain, some dating back to the Pliocene, also are home to amphiuma fossils. Incidentally, genetic tests determined all 3 amphiuma species descend from an ancestral species that lived 4-10 million years ago.
While reviewing existing amphibian species in Georgia along with the Pleistocene fossil record, I didn’t gain any surprising ecological insights, as I frequently do with mammals and birds. Not many, if any, amphibian species in Georgia became extinct at the end of the Pleistocene. However, the fossil record is incomplete, and therefore deceiving. Reference sources on this subject are limited to a difficult to obtain academic book written by the late Alan Holman, but I’m pretty sure amphibians didn’t take the big hit that the Pleistocene megafauna did. In any case it’s obvious that western spadefoot toads were once a continuous population with the eastern spadefoot toad. Speciation probably occurred some time during the early Pleistocene. And northern leopard frogs must have had a more southerly range because their present day range was under glacial ice during the Wisconsinian Ice Age.
Here’s a review of every known amphibian species in Georgia.
The Giant Salamander Family
–Also known as devil dog, it’s restricted to fast moving mountain streams here in Georgia. A Japanese cousin of this species grows to 5 feet long. Wow!
The Siren Family
Dwarf siren–Pseudobranchus striatus
Lesser siren–Siren intermedia
Greater siren–Siren lacertina
–During droughts, these eel-shaped creatures encase themselves in mud and become dormant. They “yelp” when captured. They’re restricted to the coastal plain in state.
The Newt Family
Striped newt–Notophthalmus perstriatus
Eastern newt–Notophthalmus veridescens
The eastern is interspersed throughout the state.
The Mudpuppy/Waterdog Family
Alabama waterdog–Necturus alabamensis
Dwarf waterdog–Necturus punctatus
Mudpuppies live in mountain streams; Alabama waterdogs live in the western part of Georgia; dwarf waterdogs live in the southeastern part of the state.
The Amphiuma Family
Two-toed amphiuma–Amphiuma means
One-toed amphiuma–Amphiuma pholeter
Three-toed amphiuma–Amphiuma triactylum
The species that lives in Georgia can grow to almost 4 feet long. These slippery, eel-shaped animals, bite when handled.
Photo from google images. Note the vestigial limb.
The Mole Salamander Family
Flatwoods salamander–Ambystoma cingulatum
Jefferson salamander–Ambystoma jeffersonianon
Spotted salamander–Ambystoma maculatum
Marbled salamander–Ambystoma opacum
Mole salamander– Ambystoma talpoideum
Tiger salamander–Ambystoma tigrinum
–The flatwoods salamander lives in wet pine savannahs and is often found in crayfish burrows.
–Jefferson’s salamander doesn’t currently live in Georgia but may have occurred here during the Ice Age because most of its current range was under glacial ice.
–Spotted salamanders live underground on forested hillsides near pools of water.
–Marbled salamanders lay eggs when their nests fill with rain water.
– Tiger salamanders frequently are found in my yard. They feed upon insects, worms, mice, and other amphibians.
The Lungless Salamanders
Green salamander–Aneidas aenus
Seepage salamander–Desmognathus aenus
Southern dusky salamander–Desmognathus auriculatus
Dusky salamander–Desmognathus fuscus
Imitator salamander–Desmognathus tutor
Seal salamander–Desmognathus monticola
Mountain dusky salamander–Desmognathus ochrophaeus
Black bellied salamander–Desmognathus quadramaculatus
Two-lined salamander–Euricea blisineata
Long-tailed salamander–Eurycea longicauda
Cave salamander–Euricea lucifoga
Dwarf salamander–Euricea quadridigitata
Tennessee cave salamander–Gyrinophilus palleucus
Spring salamander–Gyrinophilus porphyriticus
Georgia blind salamander–Haideotriton wallaces
4-toed salamander–Hemidactylium scutatum
Shovel-nosed salamander–Levrognathus marmoratus
Zig Zag salamander–Plethrodon dorsalis
Slimy salamander–Plethrodon glutinosus
Appalachian woodland salamander–Plethrodon jordani
Southern red-backed salamander–Plethrodon serratus
Mud salamander–Pseudotriton montanu
Red salamander–Pseudotriton ruber
Many lined salamander–Sterechilus marginatus
–Southern dusky salamander can change color like anole lizards.
–Black bellied salamanders originally were restricted to the mountain region, but their use as fish bait has expanded their range to include an irregular inhabitation of the piedmont.
–Cave salamanders have a prehensile tail and forage in cave crevices.
–Georgia blind salamanders live in ground water in southwest Georgia.
–Slimy salamanders secrete a glue-like substance difficult to remove.
Photo from google images of a Georgia blind salamander. They live in well water.
Burrowing Toad Family
Eastern spadefoot toad–Scaphiobus holbrooki
–This animal can survive light brush fires.
The True Frog Family
Crawfish frog–Rana areolata
Green frog–Rana clamitans
Pig frog–Rana grylia
River frog–Rana heckscher
Pickeral frog–Rana palustrus
Northern leopard frog–Rana pipiens
Southern leopard frog–Rana sphenocephala
Wood frog–Rana sylvatiea
Carpenter frog–Rana virgatipes
–Bullfrogs eat birds, mice, other frogs, crayfish, insects, and minnows. Their croak sounds like a cow lowing.
Photo from google images of a bullfrog.
–Green frog croaking sounds like a banjo twang.
–Pig frog croaking sounds like pigs grunting.
–River frogs and pickeral frogs have a toxic skin secretion that repels snakes.
–Southern leopard frogs escape predation by leaping into the water, making a sharp right turn, and emerging in vegetation close to shore.
–Northern leopard frogs no longer occur in state but I suspect they did during the Ice Age.
–Wood frogs live as far north as Alaska where they survive being frozen in winter. In Georgia they live in the northern part of the state.
–Carpenter frog croaking sounds like the hammering of carpenters.
The Narrow-mouthed Frog Family
Eastern narrow-mouthed frog–Gastrophryne carolinensis
–The narrow-mouthed frog’s croaking sounds like a sheep bleating.
The Toad Family
Oak toad–Bufo quericicus
Southern toad–Bufo terrestis
Fowler’s/Woodhouse Toad–Bufo woodhousei
–The southern toad likes sandy soil in oak scrub habitat.
The Tree Frog Family
Northern cricket frog–Acris crepitans
Southern cricket frog–Acris gryllus
Pine barrens tree frog–Hyla andersoni
Bird-voiced tree frog–Hyla avivoca
Cope’s gray tree frog–Hyla chrysoscalis
Common gray tree frog–Hyla versicola
Green tree frog–Hyla cinerea
Spring peeper–Hyla crucifera
Pine woods tree frog–Hyla femoralis
Barking tree frog–Hyla gratiosa
Squirrel tree frog–Hyla squirella
Little grass tree frog–Limnaoedus ocularis
Mountain chorus frog–Pseudacris brachyphone
Brimley’s chorus frog–Pseudacris brimleys
Southern chorus frog–Pseudacris nigrita
Ornate chorus frog–Pseudacris ornata
Chorus frog–Pseudacris triseriata
–Pine forest tree frog croaking sounds like a chorus of typists. They live at the tops of trees in open pine savannahs.
Photo from google images of a pine forest tree frog.
–Barking tree frogs have scattered relic populations. They probably had a continuous range during warm interglacials.
–Brimley’s tree frog changes color for camouflage.
Behler, John; and F. Wayne King
The Audubon Society field guide to Reptiles and Amphibians